PFAS Contamination Rankings

10 data-driven rankings of PFAS contamination across US states, cities, and water systems, from official EPA UCMR monitoring data. The highest city/system readings are historical peaks (largely EPA UCMR3, 2013-2015 – the most recent nationwide round with systems above the 4 ppt limit).

Quick Answer

This index links to 10 pages organized into 4 categories for easy browsing.

State rankings (2)

States With the Worst PFAS Contamination See which US states have the highest PFAS contamination levels in drinking water. Rankings based on EPA UCMR5 testing data.
States With the Strongest PFAS Regulations Massachusetts, New Jersey, and Michigan set PFAS MCLs below the federal 4 ppt cap. Here are all 11 states with stricter PFAS rules than the EPA – ranked by how strict.

City rankings (3)

Cities With the Highest PFAS Levels in Water Ranking of US cities with the highest PFAS forever chemical levels in drinking water based on EPA testing data.
Cities Near Military Bases With PFAS Contamination Cities near military bases face elevated PFAS levels from firefighting foam (AFFF). See which communities are most affected.
Cities With the Cleanest Drinking Water (Lowest PFAS) Which US cities have the cleanest drinking water with the lowest PFAS levels? See the rankings.

Compound-specific rankings (2)

Highest PFOA Contamination Levels in US Water Which water systems have the highest PFOA levels? See rankings of the worst PFOA contamination in US drinking water.
Highest PFOS Contamination Levels in US Water Which water systems have the highest PFOS levels? See rankings of the worst PFOS contamination in US drinking water.

Other rankings (3)

States With the Safest Drinking Water (Lowest PFAS) Which states have the lowest PFAS contamination? See the safest drinking water rankings based on EPA data.
States With Most Improved Water Quality (10-Year Trend) Which states have seen the biggest improvements in PFAS contamination levels? 10-year trend analysis from UCMR3 to UCMR5.
States With Worst Declining Water Quality Which states have seen PFAS contamination get worse over the last decade? See the alarming trends.